An inventive collection of word-based puzzles printed on high quality cards (front and back). Each puzzle takes from 5 to 15 minutes to solve.

Quoted: Amazon.com: Genius Deck Word Puzzles (Genius Decks): Chronicle Books: Books

Roy's Puzzazz application got mentioned on the AppEngine blog. Very cool!

Two surprises-

Dave Schappell (Teach Street) authors a "reader blog" at the Seattle PI).

He covered Roy Leban's Puzzazz web site (started at the Google AppEngine Hack-a-thon this summer).

Roy's new puzzle-a-day site.

Quoted: Puzzazz provides a quick, fun puzzle of the day each and every day. Invite your friends for friendly competition. Whether you're a casual puzzler or a serious puzzle addict, Puzzazz can fill the bill.

Zach's greatly improved the look of this sample app - and now the Save dialog comes up when you try to create a save (you need to fill in username, password, and email address to create an account).

Roy Leban did puzzle #16 in this crossword collection from the New York Times.

Quoted: Amazon.com: The New York Times Will Shortz Presents I Love Crosswords: From the Pages of The New York Times (Will Shortz Presents...): The New York Times, Will Shortz: Books

There are only 5 billion essentially distinct Sudoku puzzles (solutions) (proof here using Group Theory and Burnside's Lemma).

Interesting article on rating the difficulty of Sudoku's and various solving methods (including a short backtracking program written in Ruby).

Really interesting problem in recreational mathematics - try to reverse a unit line segment via translations/rotations - but in doing so sweep out a minimal area.

PI/4 is the obvious minimum - but it turns out you can do so in an arbitrarily small area.

What's odd to me, is that any combinations of moves that are either a) rotations about the center and b) translations, CAN NOT achieve an area less than PI/4; so it's counter-intuitive that you can do better than that.